There is known a disk auto-changer as shown in FIG. 32. The disk auto-changer 201 comprises a disk cartridge 204 hierarchically containing a plurality of trays 203 with disk recording mediums (refer hereinafter to as disks) disposed thereon, an elevator or elevating unit 205 arranged opposite to an opening of the disk cartridge 204, a movement control mechanism 206 for moving up and down the elevator 205 to the position of a desired tray 203 contained in the disk cartridge 204, and a loading mechanism 207 for drawing the tray 203 from the disk cartridge 204 into the elevator 205 or return it from the elevator 205 to the disk cartridge 204. The loading mechanism 207 is provided on the top face of the elevator 205.
As shown in FIG. 33, the loading mechanism 207 comprises a tray engaging portion 208 engaged with a hook portion 203a provided on the tray 203, a rotary arm 209 for moving the tray engaging portion 208 in the tray drawing direction or tray pushing back direction (refer hereinafter to as tray loading/unloading direction), and an arm rotating mechanism 210 for rotating the rotary arm 209.
The tray engaging portion 208 moves along a guide slot 212 with a pin 211 provided on the top face thereof inserted in the guide slot 212 provided on the top face of the elevator 205.
The rotary arm 209 is rotatably mounted on the top face of the elevator 205 by a shaft 213. The rotary arm 209 has one end provided with a slot-like shaft operation hole 214 having the pin 211 on the top face of the tray engaging portion 208 inserted therein, and another end provided with an arc-like rack 215 with the shaft 213 as center.
The arm rotating mechanism 210 comprises a pinion 216 meshed with the arc-like rack 215 and a motor 218 for rotating the pinion 216 through a gear train 217.
When rotating the pinion 216 counterclockwise by the motor 218, the rotary arm 209 rotates clockwise about the shaft 213 to move the tray engaging portion 208 in the tray drawing direction. When reversely rotating the motor 218 to rotate the pinion 216 clockwise, the rotary arm 209 rotates counterclockwise about the shaft 213 to move the tray engaging portion 208 in the tray pushing out direction. θ indicates the range of rotation of the rotary arm 209.
Then, due to its structure that the tray engaging portion 208 is moved by the rotary arm 209 as described above, the loading mechanism 207 of the above conventional disk auto-changer 201 raised the following problems:
(1) The existence of the range of rotation θ of the rotary arm 209 increases its occupation space, leading to deterioration of the efficiency of an installation space of the loading mechanism 207.
(2) With change in angle of rotation of the rotary arm 209, a force working on the tray engaging portion 208 changes, resulting in difficult movement of the tray engaging portion 208 by a uniform force.
The present invention is made to solve the above conventional problems, and allows an improvement in efficiency of the installation space and movement of the tray engaging portion by a substantially uniform force over the overall range of movement of the tray engaging portion.